Rotary drive trip hammer



May 26, 1931.

s. J. BOYD ROTARY DRIVE TRIP HAMMER Filed Jan. ll, 1928 .u n 5 e /\4 w, Vy M3@ x J .w 5 3 ...w .fr www 4 x 10 a A w 4 .45 l 6 5 w 7 24 Il 6 W 3 Hr. 7 1 6 V 6 r1 6./ .K i. H

Patented May 26, 1931 PATEN ,sorua ortica. l

SAMUEL J. BOYD, F LOS ANGELES, CALFORNIA ROTARY DRIVE TRIP HAMMER Application led January 11, 1928. Serial No. 246,074.

My invention is a rotary drive trip hammer.

An object of my invention is the construction of a trip hammer which, by means of a rotary driveis raised or pressed back against the resistance of a driving spring and on each Aturn of the rotary drive device the hammer is released, being driven against an `anvil or the device tobe operated on, such as a tool.

A further object of my invention is a trip hammer having a rotary drive device which may be connected to a rotary chuck of any type of power mechanism, such as a rotary Y drill, and such drill has an arm with a 'roller Q mounted thereon which engages a partial screw-shaped cam. -This cam lifts or presses back the hammer against the resistance of the lcompression spring and, on a part rotation', releases the hammer Vto allow it to drop or be 20 forcedagainst the tool.` The mechanism is ar- Vlranged so that as the arm continues-its revolution, it will again engage the cam and thus force the hammer back into position for the power stroke.

'7525 l A further object of myinvention is theconstruction of a rotary drive trip'hammer of a simple construction in which the hammer may be supported in one hand, the driving tool, if necessary, being supported by the other hand,

nu e0 and the hammer being 'eoprocatngly mount' ed in a casing zor holder and guided in a 'straight' reciprocating motionthere being a compression spring to give the power stroke. The power drive is through the cap or cover iti-315 of the casing and a rotary shaft mounted therein is connected in a manner to allow simple assembling of the device and disassembling for repairs, or the like.

My invention is illustrated inthe accoml 40 panying drawings, in which:

vto Fig. 3. Y

In constructing my invention I utilize a casing or housing 11 which has aV lower section 12 with preferably cylindrical walls 13' and a horizontal base 14. Thisbasehas a neck 15 extending downwardly therefrom, such neck 55 being shown as having an angular passage 16 therein, this being shown as hexagonal ,such passage is adapted to form a mounting for a tool, indicated dotted by the numeral "17. The base has a bore 18 for the projection of part of the hammer, as described hereunder, this being concentric tothe passage l16. A. handle 19 is secured to one side 'of the lower section 12. This section also has an annular recess 20 with a flat ring 21 secured to the "5 base above such recess by screws 22, the recess .Y forming a space for packing or the like. There are also guide studs 23 threaded through the walls, said studs having guide ends 24 fora purpose hereunder setforth. ""5 There is a fiber washer 25 `fitted in the baseat 'the angle of the base with the sidewalls 13.

The hammer, designated generally by the numeral 30, has preferablyV a cylindrical body portion 31 with vertical grooves 32 therein, '55 v these grooves engaging the guide ends 24 of the studs V23. There is a projecting hammer end 33 which extendsY through the bore 18 and is adapted to give the hammer stroke on the tool 17. -The hammer has a large coredout section 34 which has a cam 35 formed on one side. This cam at one end has a thin section 36-and at the other end a thick section 37, whereby the surface 38 conforms to a helical thread to allow lifting of the hammer ,as 85 hereunder set forth. At the base of the hammer there is an annular shallow recess 39 with air ducts 4O A connecting therethrough from the top of the hammer. An annular ledge 41 forms the seat 'for a compression spring 42 9@ Awhich bears on this seat and on the cap or cover, as hereunder set forth, there being a lspac'zing shoulder 42 centering the lower end of the spring. The hammer is provided with a plurality of sockets 43 in which are fitted 95 compression sprir-O's 44, these springs bearing on the base to lessen the ar; of the lower annular edge 45 of the hammer on thewasher 25. The upper part of the hammer has preferably an exterior cylindrical surface 46. 10o

The cover 50 is f-ormed with a downwardly extending flange 51 which is illustrated as having a screw-threaded connection with the walls 13 of the lowersection of the casing, and this cover has a ring like fin 52 which fits over the outside Vsection 46 of the hammer with a clearance,such iin functioning to center the top of the spring 42 in its-bearing against the under side of the cover. There is a bearing section 53 with a bore therethrough extending downwardly through the cover and above this there is a larger bore 5 4 having an annular ledge 55 for-a purpose hereunder set forth.

attached to he engaged by a chuck illustrated dotted at 61. rl`his spindleJI has an annular shoulder 62'fitting in the large bore 54'and mountedv on antifriction bearings 63 ,v the lower bearing fitting on the ledge 5,5 and the upper bearing on the lower face ofthe shoulder 62. A gland 63 is bolted tothe cover andv has a packing 64 therein. The lower end 65 of the spindle has a screw-threaded socket 66 whichrengages the upper screw threaded end of the rotary shaft 67 this shaft has a lateral arm 68 at the bottom withv a journal stud 69 fitting therein. This stud has a screw'- threaded section 70, a cylindricalsection- 71 and a head 72. The cylindrical section forms a mounting for the roller 73.

rlhe manner of operationu and functioning of the hammer is substantially as follows: Ars willv be seen from Fig. 3, the cam 35 only occupiessubstantially half of the-bore 34 so ythat the arm 68 may be inserted downwardly into the lower part of this bore, a: rollerpassing in the portion unobstructed by the cam.

When the spindle is rotatedby'V any suitable chuck 671, such as therchuck of an electric drill, the arm 68 carrying the roller 7.3 isrotated. Thisroller engages first underneath the end 36 of the cam 35 and follows the cam surface 38 tothe thick section 37.

' `On the rotation of the roller, the hammer is lifted on account of the roller running on the eamsurface 38 and such action comy presses the spring 42.. As this cam, as above mentioned, is only substantially half a.A circle in length, when the rollerv passes od the end ofthe cam surface at the thick section 37, the compression spring 42 forces the hammer downwardly.V y f Y ThisY downward power stroke` causes the hammer end 33 to strike the tool 17 heldin the passage 16. Should the device vbe operating idle, that is,`withcut the hammer end striking the tool, the springs 44 take'up a certain amount of the j ar of the hammer Vand '1: prevent the fiber washer 25 from being hammered to pieces. rlhe air ducts 40 allow free passage of air from the annular' shallow recess 39 to the top of the hammer and the reverse on the up and down reciprocating strokes of the hammer. After'the hammer undergoes its power stroke, as the roller conl p. l wardly through the open part and to engage The drive comprises a spindle 60 whicliis'V underneath the thin part of the cam, such as illustratedat 36 in. Fig. 4.

Such construction also allows a certain Y grooves and lhavinga'hammer end Vto strike thetoolsinsaid passage, said hammer having a cored-out section with a helically'curvedcam extending partly 'thereabouts, av coverV having an inwardly extendinggjournal. sectionwith a ino' rotary A shaft mounted. therein,r` a compression springbetween the hammer and the cover,t an

arm secured to said shaft and having., a roller, the roller engaging the said cam, andi reacting` Ysprimgs .between the hammer' andV the casing',

and aspindle connected tothe shaft,.ext1end-` ingt outwardly-beyond the coverv and adapted v to directly engage a driving device, the hammerk having an annular. shallow recess inthe base with a lower annularredge, the casing having a; washer to engagesaid edge. 2.714; trip: hammer comprising in. combination a casing having a passage at one side for uinsertion of tools, a hammer having lateral vgrooves with studs 1n the casing` engaging, said grooves and having a hammer end-to'strike the tools in said passagef,.said hammer havin Va cored-out section with a helically curved cam extending partly thereabouts,l a cover having an inwardly Vextending journal section, with a rotary shaft mounted therein,

a compression spring between the hammer and the cover, an arm secured to, said sha-ft and having a roller, the roller engaging the said cam, and reactingv springs vbetween the nected to the shaft,extending outwardly behammer and theY casing,r and aspijndlej con'- yond the cover andradfapted. to directlyvengage a driving devicegthe hammer yhavingan annular shallow recess in thel base lower annular edge, the casing having a washer to engage said edge, there being a plurality of air ducts through the hammer from the said annular recess to the top of the hammer.

3. A trip hammer comprising in combination a supporting structure having a reciprocatingly mounted hammer with a central cored-out section, a shelf-like structure extending partly around the inner circumfer ence of the cored-out section and having a cam surface underneath, a rotary lifting element rotating at right angles to the reciprocation of the hammer and insertable through the open section of the shelf, said lifting element engaging the cam and elevating the hammer and allowing the hammer to drop on disengaging the cam.

4. A trip hammer comprising in combination a supporting structure having a reciprocating hammer mounted therein, said hammer having a cored-out section with a shelflike structure extending partly around its inner circumference, a-cam surface formed on the underside of said shelf-like structure,

said cam having a helical curve, a rotary shaft having a roller extending from one side thereof, the shaft rotating in a plane at right angles to the reciprocation of the hammer, the roller beingl insertable under the shelf through the open space therein and engaging the cam, thereby lifting and releastng the hammer.

5. A trip hammer comprising in combination a casing having a cover thereon and an opening in the bottom for a part of a reciprocating hammer mounted in the casing, said -hammer having a cored-out section with a shelf extending partially around its inner circumference, said shelf having a cam on its under surface, the cover having a rotary shaft journaled therein and extending therethrough with a roller on one side of the shaft insertable through the open section of the shelf and engaging the cam on the underside of the shelf.

6. A trip hammer comprising in combination a tubular casing having an opening in the base for part of a hammer reciprocal therein, said hammer having a cored-out section with a shelf extending partially around its inner circumference, said shelf having a cam surface underneath, a cover mounted `on the casing and having a depending bearing section with a large bore at the top and a smaller bore at the bottom, and an intervening ledge, a shaft having a thrust bearing on said ledge and a bearing in said bearing section, a roller extending from one side `of the shaft at the bottom, insertable in the cored-out section through the opening in the shelf and engaging a cam, whereby the rotation of the shaft lifts and allows dropping of the said hammer.

7 A trip hammer comprising in combinahaving `a bearing` in the bearing section and having a socket with a rotary shaft engaged therein, said shaft vhaving a roller on one side thereof, said roller engaging a cam on a reciprocating hammer, slidable but not` rotatably movable in the casing, the rotation of the shaft causing the roller to lift and to release said hammer, and means to force the hammer in a direction opposite to its lift.

8. A trip hammer as claimedin claim 7, the hammer having a hollow interior with a shelf extending partially around its inner surface, said shelf having a cam surface underneath, engaged by the roller, the roller being insertable through the openings in the shelf.

In testimony whereof I have signed my name to this specification.

S. J. BOYD. 

